The aim of this paper is to discuss how far physics differs frommathematics, and if a philosophy of science which uses mathematics or logicsas a model for physics would be unable to be aware of many importantfeatures of that natural science.Many functions in physics differ from those of mathematics in beingfunctional dependecies and in having a lawlike character.Physical quantities have the character of "`determinables"'', sets ofspecial entities which are presupposed by physical theories.One may suspect that physics also could not be (...) formulated in anextensional language. This cannot be true, however, since every language canbe translated into an extensional version. Neverthless the existence ofdeterminables in physics shows that physics does not only talk aboutconcrete entities like space, time, spacetime, and particles, but also aboutvalues of abstract sets like determinables, and that it thus acknowledgestheir existence. (shrink)